The present invention is concerned with a drive device for insuring a lateral translatory shifting of a lengthwise part within a machine. The drive device includes two or more spindles, each having a threaded portion, which spindles are mounted in the machine to extend parallel to each other and for free rotation with their threaded sections or portions being threadably received in threaded apertures provided in the lengthwise part. The present invention concerns, especially, a device allowing a simultaneous rotation of all spindles engaged with a lengthwise part so as to have the lengthwise part accomplish a uniform lateral translatory shifting within the machine. Such a shifting device is particularly useful, for instance, though not exclusively, in a conveying station of a machine used for processing plate-shaped workpieces and including endless belt conveyors provided on lengthwise beams themselves mounted for sliding across on bearing surfaces provided on crossbars. The device allows a modification of the position of each lengthwise beam with regard to the machine frame, as required by changes in the size and dimensions of the blanks being processed.
At present, every spindle end is provided with a toothed wheel or sprocket and a chain is used for interconnecting these wheels or sprockets. In this way, every rotary movement applied to one of the spindles by means of, for instance, a crankshaft is automatically and consequentially applied to the other spindles. However, when the lengthwise part, which is to be shifted laterally, becomes particularly long, such as to support an endless conveyor with a length of more than 2.5 m, the spacing between the spindles is increased so that the chain might develop a certain backlash resulting in an unequal rotary movement for each spindle. As the lengthwise beam shifts crosswise, interferences and canting can occur and the lateral shift becomes jerky and very inaccurate. This will result in shifting the lengthwise beam somewhat beyond the position required and then necessitate a backward movement for a partial compensation of these inaccuracies. Thus, a successful shift will depend on the operator's experience.